The present invention generally relates to protective constructions for a splice portion in which conductors of a plurality of wires exposed by removing insulating coatings from end portions of the wires are connected to each other and more particularly, to a high-quality and high-performance protective construction for the splice portion, which can be produced at low cost.
As shown in FIG. 3, a protective construction for a splice portion is known from, for example, Japanese Utility Model Laid-Open Publication No. 55-17231 (1980). In FIG. 3, conductors 2 are exposed by removing insulating coatings from end portions of a plurality of wires 1 and are connected to each other by contact bonding by a connector 3 so as to form a splice portion A. Subsequently, the splice portion A is inserted into a sacklike cap 5 made of elastomer and then, an insulating tape 6 made of vinyl chloride is wound around the cap 5 and the wires 1 so as to secure the cap 5 to the wires 1.
However, in order to prevent the exposed conductors 2 from piercing through the cap 5 made of synthetic resin when the splice portion A of the wires 1 has been inserted into the cap 5 in the known protective construction for the splice portion A, wall thickness t of the cap 5 should be increased or the cap 5 should be made of wear-resistant synthetic resin, thereby resulting in rise of production cost of the known protective construction.
Meanwhile, since the insulating tape 6 is required to be wound around the cap 5 and the wires 1, production cost of the known protective construction rises. In addition, during winding of the insulating tape 6 around the cap 5 and the wires 1, relative position of the cap 5 and the wires 1 may be shifted or the cap 5 may be detached from the wires 1 due to defective winding of the insulating tape 6 around the cap 5 and the wires 1 and thus, quality of the known protective construction becomes unstable.
Furthermore, since the cap 5 is fixed to the wires 5 by merely winding the insulating tape 6 around the cap 5 and the wires 1, holding force for holding the cap 5 and the wires 1 together is small. In addition, since gap exists between the splice port A and the cap 5, the splice portion A may be damaged when an external force is applied to the cap 5.
Moreover, since a mouth of the cap 5 is closed by only the insulating tape 6 and the gap exists between the splice portion A and the cap 5, the splice portion A is likely to be subjected to corrosion due to penetration of water into the splice portion A or damage due to salt content. Especially, in case the splice portion A is disposed in a high-temperature environment such as an engine room of a motor vehicle, water is readily collected in the splice portion A through dropwise condensation due to sharp changes of temperature and thus, the splice portion A is more apt be subjected to corrosion.